Population Structure

Demographic Transition = the change from a society with short life expectancy & high birth rates to a society with long life expectancy and low birth rates.

In more economically developed countries, there tends to be a long life expectancy and low birth rates. This leads to levelling-off of the population and the sigmoid population growth curve is re-established.

Three common types of population:

> Stable population - the birth rate & death rate are in balance, so no increase or decrease in population size

> Increasing population - High birth rate (represented by wide base to pyramid) and fewer older people giving a narrower apex to the pyramid. Typical of LEDCs.